1. Field of the Invention
The present invention relates to an oral composition having an excellent antibacterial action agent Actinomyces viscosus and effectively preventing the development of calculus and periodontitis.
2. Description of the Related Art
Calculus is a hard deposit, having a high inorganic content, formed on the surfaces of teeth, and is believed to be a major cause of the development of gingivitis and periodontis. Accordingly, an inhibition of the formation of calculus effectively prevents and cures the development of periodontal diseases. The rapid deposition of calculus can be prevented to a certain extent by brushing the teeth at frequent intervals. However, brushing alone is not sufficient for removing substantially all of the calculus deposited on the teeth.
The formation of calculus is considered to be caused by the deposition of amorphous or microcrystalline calcium phosphate on membraneous portions of bacteria or the substances between bacteria in the plaque, which gradually become dense and change to hydroxyapatite. It is known that the main bacteria forming organic matrixes in old plaque or plaques in gingival sulcus, in which the above-mentioned calcification occurs are filamentous bacteria or rod-shaped bacteria belonging to Actinomyces, Leptotrichia, Bacteroides, and Fusobacterium. Accordingly, an inhibition of a growth of these bacteria will effectively suppress the formation of calculus, and thus prevent the development of periodontal diseases.
The inhibition of the formation of plaque, and the removal of the plaque, are most important for calculus prevention, and to this end, physical methods such as brushing have been used. As mentioned above, brushing alone is not sufficient to prevent and remove calculus and, therefore, chemical methods using antibacterials such as chlorohexidine, benzalkonium chloride, and cetylpyridinium chloride have been used. However, these antibacterials can not be formulated at a higher amount, from the viewpoint of safety.
Furthermore, it is known that polyphosphates have inhibited the caries in animal tests (e.g., Journal of Dental Research, Vol. 43, p 1123-1136) and also possess antibacterial activity against Streptococcus mutans and Diphtheroids (e.g., Arch. Oral Biol. Vol. 27, p 809-816, 1982 and Infection and Immunity, Vol. 1, p 604-606, 1970). Furthermore, Arch. Oral Biol., Vol. 15, p 893-896 (1970) discloses the effectiveness of a water-soluble phosphate against the formation of calculus. In addition to the above, JP-A-52-108029 (Kokai) proposes the prevention of the formation of calculus by a combination of polyphosphates and polyvalent cations, and JP-A-59-42311 proposes an oral composition formulated with pyrophosphate of anticalculus. Thus, it is known in the art that the use of polyphosphates in oral compositions is effective for the inhibition.
However, the effects obtained from the use of polyphosphates per se are not sufficient and, therefore, there is a strong demand for the development of oral compositions having an excellent calculus preventive effect or an effective antibacterial action against filamentous bacteria.